1. Field of the Invention
The present invention relates to a wire bonding method and apparatus and more particularly to a lead-pressing method and apparatus for pressing leads which are installed on lead frames, substrates.
2. Prior Art
In cases where wires are bonded to electrodes on pellets and leads which are provided on lead frames, substrates, etc. (hereafter, both lead frames and substrates will be referred to in general as "lead frames"), the leads are pressed against a heating block by a lead-pressing plate.
In conventional lead-pressing devices, a lead pressing plate has a square window formed in it (so that the tips of the respective leads are exposed) and is installed above the lead frame. All of the leads are pressed against the heating block by this lead-pressing plate.
One example of lead-pressing devices of this type is disclosed in Japanese Patent Publication No. 59-5976.
In this and other prior art, if the lead pressing positions change due to differences in the type of articles being processed, the pressing plate must be replaced with a new pressing plate which has a square window of an appropriate size for the lead frames. As a result, the wire bonder must be stopped during the operation, thus dropping working efficiency of the wire bonder. Since a multiple number of pressing plates must be prepared in order to handle various types of articles, storage and control become complicated.